1. Field of the Invention
The present invention relates to reading data in a hard disk drive.
2. Background Information
Hard disk drives contain a plurality of magnetic heads that are coupled to rotating disks. The heads write and read information by magnetizing and sensing the magnetic fields of the disk surfaces. Each head is attached to a flexure arm to create a subassembly commonly referred to as a head gimbal assembly (“HGA”). The HGA's are suspended from an actuator arm. The actuator arm has a voice coil motor that can move the heads across the surfaces of the disks.
Data is typically stored in sectors that are located within concentric radial tracks on the surfaces of the disks. Errors may occur when reading data. There have been developed various error recovery schemes to recover data read from disk. One source of error may be stray flux from an adjacent track. The stray flux causes noise that degrades the quality of the read signal and create errors in the data. This is commonly referred to as adjacent track interference (“ATI”). Unfortunately, conventional error recovery schemes do not always compensate for errors caused by ATI.